log: add support for logging max instead of averages

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 7c24c1b74296aa33cdff97eca9458defd291b6ca..6d80360574e0c89899756cbc6a1d9838293c9c81 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1013,7 +1013,9 @@ random_generator=str      Fio supports the following engines for generating
                typically good enough. LFSR only works with single
                block sizes, not with workloads that use multiple block
                sizes. If used with such a workload, fio may read or write
                typically good enough. LFSR only works with single
                block sizes, not with workloads that use multiple block
                sizes. If used with such a workload, fio may read or write

-               some blocks multiple times.
+               some blocks multiple times. The default value is tausworthe,
+               unless the required space exceeds 2^32 blocks. If it does,
+               then tausworthe64 is selected automatically.

 
 nice=int       Run the job with the given nice value. See man nice(2).
 
 
 nice=int       Run the job with the given nice value. See man nice(2).
 


@@ -1568,8 +1570,12 @@ log_avg_msec=int By default, fio will log an entry in the iops, latency,
                disk log, that can quickly grow to a very large size. Setting
                this option makes fio average the each log entry over the
                specified period of time, reducing the resolution of the log.
                disk log, that can quickly grow to a very large size. Setting
                this option makes fio average the each log entry over the
                specified period of time, reducing the resolution of the log.

-               Defaults to 0.
+               See log_max as well. Defaults to 0, logging all entries.

 
 

+log_max=bool   If log_avg_msec is set, fio logs the average over that window.
+               If you instead want to log the maximum value, set this option
+               to 1. Defaults to 0, meaning that averaged values are logged.
+.

 log_offset=int If this is set, the iolog options will include the byte
                offset for the IO entry as well as the other data values.
 
 log_offset=int If this is set, the iolog options will include the byte
                offset for the IO entry as well as the other data values.